Ready.....Steady.....

Herbie · June 6, 2022

Can of Worms.....OPENED! :laughing:

Not really sure if this should be in the RX forum as it may only be the RX that uses this size of tyres, but anyway, just seen the following question posed in the Lexus Owners Club UK Facebook Group:

I've heard that some RX owners have swapped from 235/55/20 to 255/50/20 because of the vastly superior choice of rubber available.

Has anyone done this, and what have you noticed real-world in terms of handling and MPG?

I note that both my favourites, Michelin Cross Climate and Goodyear Vector 4Seasons, are available in the 255/50/20 size, so what are the ramifications of changing to that size on a 2018 RX450h?

NemesisUK · June 6, 2022

Initial thoughts would be a slight hardening of the ride and tighter handing but it would be very marginal. Depending on the tyre compound and construction probably any change would be lost. Winter/all season tyres tend to be 'softer'

The other question in my mind would be, what does my insurer think to the fitting of non-standard tyres?

Linas.P · June 6, 2022

I doubt it would make suspension much harder considering the size wall difference is just 2%, but you would definitely get higher fuel consumption and more road noise (because of wider tyre)... handling could potentially get better or right tyres (that is if you go with UHP), but I doubt RX is the car where it is desirable and even further I doubt all-season tyres will give you that impression. As well speedo will be another 1% more optimistic.

Boxbrownie · June 6, 2022

As the sidewall is only 1/10” lower that’ll make no discernible difference to the ride, you’ll find more difference between makes ofmtyre with differing wall construction of the same size TBH, as for insurance as mentioned above, just tell the insurance company you want to fit a set of Winter tyres to the vehicle and save the positive reply (email or hard copy) as I doubt they will question/ask if your fitting the exact same size, after all a lot of winter tyres have a lower speed rating and that doesn’t seem to bother them.

At least you will have it in writing that the modification was approved by them 😉

J Henderson · June 6, 2022

I'd definitely be up for switching if it opened up a wider range of tyres available. I did the same on my IS250 - 245s on the rear instead of 255s.

My only concern would be whether the RX wheels are wide enough to accommodate them without looking weird.

What are they? 8.5" would ideally be the minimum width needed for a 255 tyre.

Linas.P · June 6, 2022

I would not bother insurance with such minor details. As long as tyre road legal and not some stupid size (like 35" wheels from tractor) it should not matter. Insurance should not have a right to think anything about it and don't even give them opportunity.